Filter flow indicating device



FIG. 1 is a top plan view of a filter flow indicating device showing my new design;

FIG. 2 is a front elevational view of FIG. 1 the rear being substantially a mirror image thereof;

FIG. 3 is a left side end elevational view thereof;

FIG. 4 is a right side end elevational view thereof. 

The ornamental design for a filter flow indicating device, as shown and described. 